Mortise locksets usually include handles that are operably connected to retractable latch bolts by latch bolt retraction mechanisms. A typical mortise lockset includes a generally rectangular case that fits into a similarly-shaped complementary cavity formed or cut into a door. The retractable latch bolt and the retraction mechanism are supported within the case with a portion of the latch bolt extending from the case in an extended position. In the extended position the latch bolt engages a complementary recess formed in a door jam when the door is closed. When an operator turns the door handle the retraction mechanism causes the latch bolt to retract from the door jam recess into a retracted position in the mortise lockset case. With the latch bolt in the retracted position, the door is free to move from the closed position to an open position.
Most such mortise locksets also include some form of lock-out mechanism that is positioned to mechanically engage either the handle, the latch bolt or some portion of the retraction mechanism. Such lock-out features are usually mounted in the mortise lockset case and are configured to prevent the latch bolt from being retracted and/or the handle from being turned without first unlocking the locking mechanism by inserting a key or by entering some type of coded entry command on a keypad.
An example of a mortise lockset having a handle lock-out mechanism that prevents a handle portion of the lockset from being moved without first inserting a key or key card is disclosed in U.S. Pat. No. 5,474,348 issued Dec. 12, 1998 to Palmer et al. (the Palmer patent). This patent shows an electronic lock having a door handle lock-out feature that includes a motor-driven cam that moves a sliding stop into engagement in a hub to lock the hub in place. A slip clutch mechanism allows the motor to continue running after the sliding stop has been driven to the full extent of its travel into the hub. The motor is set to run for slightly longer than required to ensure that the slider is fully engaged in the hub. The door handle lock-out feature also includes a spring that stores energy when the sliding stop is either blocked or hung up by friction as it is being moved. When the blockage or hangup is overcome, the stored spring energy moves the sliding stop into the commanded position. A gearbox is connected between the motor and the cam to allow the motor to run at high speed.
The cam disclosed in the Palmer patent is a locking bar type cam with cam surfaces disposed at the end of an elongated spring arm. The motor moves the spring arm and cam surfaces through a short arc. The slip clutch mechanism disclosed in the Palmer patent is located in a pivoting hub that supports the spring arm. The run time of the motor disclosed in the Palmer patent is preset to produce one full 360° rotation.
The Palmer motor pivots the cam surfaces through an arc at the end of an elongated arm mounted on a pivot hub that includes the slip clutch. Therefore, along with the pivot hub, the cam requires a considerable amount of space within the lock case both for installation and for movement in operation. The elongated spring arm is also prone to bending, i.e., plastic deformation. Because the motor run time is preset to a constant value the Palmer lock is unable to extend battery life by limiting motor run time. The Palmer lock is also unable to determine when the sliding stop is fully engaged. The Palmer lock is also unequipped to easily adapt to applications where it may be necessary or desirable to lock-out the interior handle rather than the exterior handle.
Some electronic mortise locksets also include deadbolt position indicators that transmit deadbolt position information to the logic circuitry of the lock. For example, U.S. Pat. Nos. 5,791,177 and 5,816,083 issued to Bianco (the Bianco patents) show a controller that receives a deadbolt position indicating signal through sensors mounted on a printed circuit board. A spindle turns a communication plate which actuates the sensors. The communication plate is configured to close electrical circuits when contacting the sensors.
Some electronic mortise locksets include employee access tracking systems that help employers determine and keep track of which of their employees have gained access to which rooms in an establishment such as a hotel or office building. For example, U.S. Pat. No. 5,437,174 to Aydin (the Aydin patent) and the Bianco patents disclose electronic locks that download entry data onto key cards. The information stored on the cards includes the times and dates that the lock has been opened. However, the Aydin and Bianco locks are unable to provide a record of entry on each user's card.
Most electronic mortise locksets include some form of card reader module configured to read bar code symbols printed on key cards, magnetic strips affixed to key cards and/or to communicate with integrated circuit chips (IC chips) embedded on so-called “smart” key cards. For example, U.S. Pat. No. 4,990,758 issued Feb. 5, 1991 to Shibano et al. (the Shibano patent) shows a snap-together card reader module including a magnetic reader. Locking snaps hold the module together. A spring biases the magnetic read head against a card that is inserted into the reader module. While the Shibano lockset offers the ease of snap-together construction, it lacks dual-function components that could further simplify its assembly and operation.
Electronic locks have been designed that are both programmable and interrogatable. For example, U.S. Pat. No. 4,848,115 issued to Clarkson et al. (the Clarkson patent) shows a lock programmer including a serial port cable connected to a key. A user may insert the key into a card reader module to program a lock. However, the Clarkson lock programmer cannot be used to interrogate a lock or to apply power to the lock.
What is needed is an electronic mortise lockset handle lock-out mechanism that is more robust, requires less space within the lockset case and that can extend battery life by limiting motor run time while insuring full engagement of the lock-out mechanism. What is also needed is an electronic mortise lockset that includes: a deadbolt position indicator that does not require that open-air electrical contact be made between a metal plate and wire sensors; an employee access tracking system that provides a record of entry on each user's key card; a card reader module that can read more than one type of key card and that is easier to assemble; and that includes a lock programmer capable of performing other operations in addition to lock programming.